Simple way to install Flarum beta on any shared hosting
install the flarum on your PC, its very easy in UBUNTU without any issue
When you install it succesfully then RUN it, if its working properly on your PC then its time to ZIP the public_html folder where FLARUM is installed.
Upload the ZIP folder on your hosting server, unzip it on public_html and install it.
Possible issues with these extensions: mbstring, pdo_mysql, openssl, json, gd, dom, fileinfo
Make sure that are installed by your webserver, if not ask them to install it
Sorry! I'm not developer, I just shared my knowledge , how I installed it on my shared lightserver. ?